Testing Center

1. Quality of die-casting parts

The quality of die-casting parts includes appearance quality, internal quality, and usage quality.

Appearance quality refers to the surface smoothness, surface quality, dimensional tolerances, positional tolerances, and quality deviations of castings.

Internal quality refers to the chemical composition, physical and mechanical properties, metallographic structure, and the presence of pores, inclusions, and cracks inside the casting.

Quality of use refers to the ability of castings to meet various usage requirements and work performance, such as wear resistance, corrosion resistance, cutting ability, weldability, etc.

2. Quality standards

Quality standards include national standards (GB), international standards, or enterprise standards. China is one of the main members of the International Organization for Standardization (ISO), and international standards can be equivalently regarded as national standards.

The quality standards for castings include precision standards, surface quality standards, and functional quality standards.

3. Casting defects

There are broad and narrow definitions of casting defects. The broad definition of casting defects refers to the quality characteristics of castings that do not meet the classification standards (qualified products, first-class products, excellent products), poor quality management of casting manufacturers, and the inability to guarantee product quality.

Narrowly defined casting defects refer to all detectable defects in castings, including those listed in the GB5611-85 casting terminology standard.

Castings can be classified into three categories after inspection: qualified products, repaired products, and scrap products.

The scrap rate P of castings is the percentage of the total amount of castings (internal and external waste) to the qualified product quantity W, as well as the sum of internal waste quantity W1 and external waste quantity W2.

The defect rate of castings is the percentage of defective castings compared to the total production volume. The defect rate is usually greater than the scrap rate. The number of casting defects is expressed in pieces.

4. Casting defect inspection method

The following methods are commonly used for casting defect inspection:

Visual inspection;

Chemical analysis inspection;

Mechanical performance testing;

Macroscopic examination (macroscopic examination);

Metallographic examination;

Non destructive testing.

5. The significance of improving product quality

Quality is the lifeline of an enterprise, an important pillar for improving its competitiveness, and an important condition for improving its economic benefits.